1. Field of the Invention
The present invention relates to a system for performing an operation related to a circuit substrate such as a printed circuit board, for example, mounting circuit components such as electric-circuit or electronic-circuit components on the circuit substrate, or applying an adhesive to the circuit substrate.
2. Related Art Statement
There is known a circuit-substrate-related-operation performing system which includes a conveyor for conveying a circuit substrate ("CS") and positioning and supporting the CS, and an operation performing device for performing an operation related to the CS positioned and supported by the conveyor. For example, there is known a system of this sort which includes (a) a main conveyor which conveys a CS and positions and supports the CS, (b) an operation performing device which performs an operation for the CS positioned and supported by the conveyor, (c) a carry-in conveyor which conveys the CS toward the main conveyor and hands over it thereto, and (d) a carry-out conveyor which receives the CS from the main conveyor and conveys it away from therefrom.
As a system of this sort, there is known a circuit-component ("CC") mounting system for mounting CCs on a CS. This system includes (a) two CS conveying lines which are arranged in parallel with each other and each of which includes a carry-in conveyor, a main conveyor, and a carry-out conveyor arranged in series with one another, and (b) a CC mounting device which mounts CCs on a CS positioned and supported by each of the two main conveyors. More specifically described, while the CC mounting device mounts CCs on a CS positioned and supported by one of the main conveyors, a CS which is positioned and supported by the other main conveyor and on which CCs have been mounted is carried out therefrom by the carry-out conveyor, and another CS is carried in onto the other main conveyor and is positioned and supported thereby.
In the above CC mounting system, the CC mounting device can start mounting the CCs on the CS positioned and supported by the other main conveyor, immediately after it finishes mounting the CCs on the CS positioned and supported by the one main conveyor. Thus, it needs substantially no time to change two CSs with each other, which leads to improving the efficiency of mounting of CCs.
However, the above CC mounting system has the two carry-in conveyors and the two carry-out conveyors. Meanwhile, an upstream-side device is provided on an upstream side of the CC mounting system in a direction of conveying of CSs, and a downstream-side device is provided on a downstream side of the CC mounting system. The upstream-side device hands over a CS to the CC mounting system, and the downstream-side device receives the CS from the CC mounting system. The upstream-side device may be a CS supplying device, another CC mounting system, or an applying system which applies an adhesive or a solder paste to CSs. The downstream-side device may be another CC mounting system, an adhesive curing furnace which cures or hardens the adhesive temporarily fixing the CCs to the CS, a solder reflowing furnace which reflows or melts the solder for electrically connecting the CCs to the CS. Generally, the upstream-side device has only a single CS-hand-over portion, and the downstream-side device has only a single CS-receive portion. Accordingly, a CS receiving and distributing device is needed which receives CSs from the CS-hand-over portion of the upstream-side device and distributes the CS to the two carry-in conveyors, and a CS collecting and handing-over device is needed which collects the CS from the two carry-out conveyors and hands over the CS to the CS-receive portion of the downstream-side device. This leads to complicating the construction of the CC mounting system, thereby increasing the production cost of the same. This problem will also occur to other systems which include operation performing devices other than the CC mounting device.